Tsunami

Etymology

From Japanese tsunami, “harbor wave,” from tsu (“harbor”) plus nami (“wave”) — so named because the waves rear up destructively in harbors even when they pass almost unnoticed in the open ocean. It has largely displaced the misleading English term “tidal wave.”

noun · /tsoo-NAH-mee/
A series of enormous, destructive sea waves set off by an underwater earthquake or landslide.
What it names
The wall of water thrown up by a sudden shift of the seafloor — and, figuratively, any overwhelming surge that arrives all at once.
Example
The listing triggered a tsunami of orders that crashed the site within minutes.
Related idea
A tidal wave is caused by tides; tsunami is the accurate term for waves from earthquakes or landslides, which have nothing to do with tides.